Interest in structures which can protect people and property in collapsing buildings has markedly increased in the recent past. Much of this interest has been prompted by the need for increased earthquake preparedness, especially on the West Coast. As was seen in the recent earthquakes in Mexico City and San Francisco, an earthquake can cause the collapse of many man-made structures, even recently constructed structures. Without some sort of protective structure, lives and valuable property can be wiped out in an instant.
Several attempts have been made to construct protective structures, especially bed structures. Most of these structures, however, are strictly of a "box" type, wherein all of the corners are right angles. Such a box type protective structure is vulnerable to lateral moments.
Also, all of the previously known protective structures are of a fixed size, and cannot be easily expanded or made smaller to meet the changing needs of the user.
Accordingly, there is a need for a protective structure with increased strength over conventional box-type structures. There is a also a need for a protective structure which is easily expandable and contractible.